CNBC's John Harwood on Friday talked with Sen. Sherrod Brown, D-Ohio, who is up for re-election on Nov. 6. Here, they discuss the increasingly heated political climate in the U.S.

John Harwood: We've had this spate of now a dozen potentially explosive devices mailed to people in politics. What do you make of that? I was with your longtime colleague in Ohio politics, John Kasich, yesterday. And he was putting some of the blame on President Trump for things he's said. Do you see it that way?

Sherrod Brown: I don't want to point fingers. I have a debate tonight with my opponent. And I will ask him to join me in asking the president to try to unify the country. I remember when President Bush, with whom I vehemently disagreed on trade policy, on tax cuts for the rich, on the Iraq War, right after Sept. 11, went to a mosque because he wanted to unify the country. And I wish this president would stop the divisive rhetoric. And I wish this president would respect your profession. And I'm not saying that because I'm sitting with someone from your profession.

Harwood: You might be married to someone from that profession.

Brown: I am also married to a journalist. But long before that, I never believed that the media were the enemy of the people, or that they don't play an important role. In fact, if anything, the media's role in keeping politicians and business honest has fallen back. There aren't enough reporters at the statehouse in Columbus or at the Capitol in Washington.

There are not enough investigative reporters nosing around on Wall Street or at capitals. That, to me, is the biggest shortcoming of the media. Not that in any way, they're enemies of the people, but there are not enough of them. The big media companies are making money, but they're not hiring reporters and they're not paying them well. And they're not hiring investigators to do what needs to be done to keep our democracy strong and vibrant.

Harwood: You hear a lot of pessimism these days about the state of our democracy and the political debate. Are you pessimistic, or not?

Brown: I'm really never pessimistic. I think this is a troubled time. I think this president has added to the divisions – I mean, we were a divided country before Donald Trump, but he's made it much, much worse. We have one network that doesn't really believe in truth-telling, frankly. And the number of people that still believe Barack Obama wasn't born in this country, or the number of people that think John McCain wasn't a hero because he left Vietnam and used his father's connections, when it was exactly the opposite – that comes from a news organization that has put out those untruths.

My biggest concern for the country is how we govern. My biggest long-term concern is, first, climate change and this government now, the Republican leadership, has simply failed to acknowledge it. That worries me. I'm worried about the long-term impact on the judiciary, of young, very far-right, very much out-of-the-mainstream judges from district court all the way up to the Supreme Court. It's hard to govern when a quarter of the country gets its news from a source that's not really news. And so, we've got to figure that out as a nation.